Psicothema was founded in Asturias (northern Spain) in 1989, and is published jointly by the Psychology Faculty of the University of Oviedo and the Psychological Association of the Principality of Asturias (Colegio Oficial de Psicología del Principado de Asturias).
We currently publish four issues per year, which accounts for some 100 articles annually. We admit work from both the basic and applied research fields, and from all areas of Psychology, all manuscripts being anonymously reviewed prior to publication.
Psicothema, 2008. Vol. Vol. 20 (nº 4). 896-901
Paula Elosua Oliden y Bruno D. Zumbo*
Universidad del País Vasco y * University of British Columbia (Canadá)
El coeficiente alpha de Cronbach es usado constantemente en las ciencias sociales como estimador de la consistencia interna de las puntuaciones. Sin embargo, el supuesto de continuidad en el que se asienta este estadístico es sistemáticamente violado con la utilización de escalas de respuesta ordinal o escalas Likert. Dado que existen coeficientes de fiabilidad construidos sobre la consideración ordinal de los datos a analizar, los coeficientes ordinales alpha y beta, el objetivo de este trabajo es presentarlos, aplicarlos, exponer cómo se estiman y mostrar sus ventajas e inconvenientes respecto a la estimación tradicional de alpha.
Reliability coefficients for ordinal response scales. Cronbach’s alpha is systematically used in the social sciences to estimate internal consistency. However, this coefficient assumes the continuity of the variables and this assumption is not met by ordinal response items or Likert scales. This work shows two alternatives to the alpha coefficient, the ordinal alpha and beta coefficients. Both of them take into account the ordinal nature of the data. The new coefficients were applied to several scales and compared with the traditional estimation of alpha. This paper also shows how to estimate those coefficients.